Process of producing calcium cyanamid.



A. BONNINGTON &'H. G. AKERS. PROCESS OF PRODUCING CALCIUM GYANAMID. APPLIGATIYON FILED FEB. 16, 1011.

1,021,445 1 Patented Mar. 26, 1912.

I 'INVENTORS- WITNEMES'.

FWYMMM at? M; F

A TTORNEY.

UNITED STATES PATENT OFFICE.

ALEXANDER BONNINGTON AND HARRY Gr. AKERS, OF TORONTO, ONTARIO, CANADA.

PROCESS OF PRODUCING CALCIUM Ci'ANAMID.

1 ,osei .445.

Specification of Letters Fatent.

Patented Mar. 26,

Application filed February 16, 1911. Serial No. 608,996.

To all who-mit in (13 concern Be it known that we, iliacxaixnuu Box- NING'I'ON and IlARRY G. Auras. of the city of 'loronto, in the .iro'vincc of Untario, Canada, have invented certain new and useful Imprm-ernents in Direct Processes of Producing a-lcium Cyanaruid. of which the following is a specification.

This intention relates to the direct production of AlCllHll cyaluin'iid and our object. is to devise a cheap and cilicicnt direct. process which Will result in the formation of the cyanamid pra-ictically free from cal-hid an. end product.

The process based on the following reactions that is to any that in carrying outv the procthe calcium cyanamid is formed by talcing proper qiuintities of calcium carl'mnate or an equivalentv calcium cou'ipound carbon in a suitable form and a catalytic agent, in timately mixed together with a. suitable binder, and heating them together to the temperatureof reaction in the prcecnce of nitrogen and then allowing the mass to cool in the presence of nitrogen.

The cyana'mid may be formed directly as in Formula- 1 or 2 or calcium carbid may he formed, which, by a further reaction as in Formula 3, unites with the nitrogen releasing carbon.

Thefundamental features of our process lie. in so preparing and treating the mixed materials employed before subjecting the mixture to the temperature of reaction. that a porous mass will be produced which is readily permeable by the nitrogen employed, in the use of the catalytic agent to reduce the tempo allure of re-action and in the linal treatment of the porous mixture in a furnace in which the process of mamifacture may be continuous.

be either calcium fluorid ((31 calcium chlorid (CaCL) metallic iron iron' oxid or other suitable substancev though the calcium lluorid. alcium chlorid or a mixture of both ix dccu'led preferable. The binder employed may be pitch. tar, sugar residues or the like, or even inorganic compounds having a. melting point lower than the calcium carbonate or oxid employed. example of such a binder. Calcium chlorid or tluorid also have an'action as a hinder and may thus ha re value in this capacity as well as a catalytic agent. The calcium earbonate or its equivalent. the coke or its equivalent. and the catalytic agent, are finely ground,- and suitable quantities are taken and intimately mixed with the binder, preferably pitch or tar. also be employed if considered. necessary. The mixed material is then cokcd in any suitable coking furnace, being.- hakcd. or heated to a temperature below that of reaction but vuuliicicnt to carbonize the hinder. This preliminary coking: leaves the-mass in a hard porouu condition in which it is readily permeable by the nitrogen introduced in the later stages of the process. The pro duction of this porous mass due partly to the carbonizing of the binder and partly, if calcium carbonate be employed. to the driving oil of carbon ilioxid from the .arbonate. This porous charge is now subjected t0 in tense heat, preferably such that. obtainable through the use. of an electric furnace, though the temperature preferably lie 1:

bclowthat' at which calcium carbid is ore i narily formed and preferably in the neighborhood of 1600 C.

The form of furnace preferably to be em ployed is that m \\'l1l(ll the charge may be (-(illllIlHOlh-lY passed through the heated zone' so that after a portion of the charge has been heated to cause the reaction, it passes on to a cooler zone. The drawing illustrates a suitable furnace for the purpose.

is the body of the furnace forinecl of suitable refractory materials. The chamber of the furnace is of-comparatively small diameter relative to its length, and in the upper end is inserted an electrode B. The s'ecorul electrode C preferably ring shaped and located at. the lou'er end of the furnace chamber A. communicates with the Water jacketed chamber 1) which discharges into the chanr ber of the screwcom'eyer E which feeds Some water may The lower end of the furnace to the dimsharge pipe G. TIN: discharge proforabiy t-nntroliec'l by a. pivoted 'miru H. The porous IOZISiICd matnriai fed into the uppr end of the furnace, passes down through the hunted 1' I10 and after the reaction has taken place. grachmiliy Cools and. i3 dischargmi from the discharge pipe (3-. Nitrogen may be introduced through the opening I. Nitrogen assed through the nmss both m-hiie it. is passing anti after it has passed the heated Zane resulting in rezicition taking li hwv according to furi'n'uhn 1 $2 or 3, hereinhe '1 set Out. The. re it that an and product We niiitirin miiuhzm cyanmnid pmcticz-aiiy free from calcium can hith hut. coi'itnining of course the czamiytir: sign it emphiym'i which, however, is nut ohjectioliabie.

The nth-xiii our pra ses? 3113'- L piste, it is react mi. does not requirethe pr'eiiinina. V fornmtion of calcium cwnrbiii and its suhseq mnt trezihnent t0 produce the cyanainiti. A. secnnd great wch-zmtzige is; that file cyanzimiti is produced practically free from carbiiii The success 0f the process ciepemis, on the forming Of the charge as spnngy mass anti the maintenance of this crinditiun to the 817K} of. the prncess in urtier to permit (if the nitr 'igen thoroughly and cm'npietaiy permeating the mass during such time reactiontakes piacsa; and seen-nil, frmn. the use of the caitalyt-ie again:- which makes it feasible to carry the react-inn on at a lmver tsgmprature than wouid, otherwise. he the case thus tenti'ing to prevent the fornmtimi of carbiti and which further acts by iteaning the ina s porous and by cqndncting the heatthrnugh'the charge.

W'Vhat We. claim as our inventinn is 1. A direct process of mgnufncturing cal-- ciuxn cyanamid which censists in first form ing'za, porous mass containing in intimate acin'ii-xturevcalciuzn in combination, and car bongnnd then heating said mixture to a suitable tmperatnre; and passing niti sgan through the 1 2-. A direct process; of manufacturing 02th cium cynnamid which consists in first forming a porous mass. containing, in intimate admixture calcium carbonate, and carben'; and then heating said mixture to a. suita-ble' temperature, and passsing nitmgen through the mass.

3. .A'direct process of manufaaturing caicium oyanamid which consists in forming a porous masscontaining, in intimate (1,(1 mixture, calcium carbonate and carbon; passing said mixture thmngh a heated zone in :1 .t' urm :e.in which re-:i0tim1 hikes [)iiLCC; panning nitrogen through the heated inn 5s rind :iihiwing the mass: tn (not in tho presence of the uilrognn.

A direct ]')1IH('($$S 0F insmu'hu-ttiring; (uh ciulu ryu'munici which (rniisishe in forming a porous nmss (:nnmining; in' intimate miinixture mhzimn ('ni'honulv u catalytic agent and carb n; passing Sili'i mixture lhruugh rt ho-xtmi mmin a furnace in which T0 uiimi takes pinch; introducing nitrogen int; he 53121.55 and :ilimring the ma. to mini in thn west-mic (it the nitrogizn.

5. xi (iii-00tprm' H hf mzmui'zi hiring (::2i- 0.2mm i'ryiinumici which cnnsista in "forming a martini; n'ims sun niiiing, in intimate mi mixture. (-nh'iuui t'nrhnnnir uu-icinm Hum-iii, and (:nrhun: parking said Xturu through :i heat-ed zone in it i." mum: in which inaction lzzhcs 3; iiiti'uthnring nitrogen in'm ihe mass and nihming the mass to 0001 in the present-0 oi? the nivn A LiiIQC'C prot s of manufacturing calcium C ilEKZIJ'I'IiR i M15 .11 QO RS STJ-E in mixing; i0" gather caihzimn (":lYiiOllzii-E, CtUiilOI] and :1 hincier; baking the mixture in obtain a hard porous mass, passing the; balm} mixture thi'migh t heats-1i zone in iui'nace in which I n takes place; and. mthe same time, pats n 'nirogmi thi'tmgh the Inns '2". A tiiiuct FITNESS; manufacturing cainnnmid which; consists: in mixing t gather uahsiiiln cazriin'izisite, caifbnn, a catalytic ngnnt and hinder; linking; the, mixture to obit: in :1: hairci pin-0119mm s; passing the haflknr i mixture thrmi hen-ind. 20:10 in :1, furnace in which ret, ion take-: plane; and at thg mime time, pmssing nitrogen thruugh the mass.

A direct pmcann of manufacturing calcium cyimamid. which consists in first linking a mixture of caiciiun carbonate, carbon and ilbinder; and then heating said mix turn to a suitable temperature; and at the same time passing nitrogen through "the mass.

9i direct.- process of manufacturing cal- J. Enw. MzfYimic,

. '0 E. P. I'IALL, 

